94 research outputs found
Effects of salinity, temperature, light intensity and light regimes on production, growth and reproductive parameters of Apocyclops dengizicus
The effects of salinity, temperature, and light conditions on production and development, longevity, survival and sex ratios of the cyclopoid copepod, A. dengizicus were determined. Seven different salinity levels (5, 10, 15, 20, 25, 30, 35 psu), four temperatures (20, 25, 30, 35 °C), three different light intensities (33.3, 85.3, 162.1 μmol photons/ m^2/ s) and light regimes (24:0, 0:24, and 12:12 h light:dark regime) were employed. The highest production was achieved under 20 psu salinity. The optimum temperature required for the maximum reproduction and shortest development time was 35 °C. The production was highest (p<.05) and development rate of A. dengizicus was shortest (p<.05) under the lowest light intensity (33.3 μmol photons/ m^2/ s). Continuous light (24:0 h LD) showed positive effects on growth and production. Light regimes 24:0 h and 12:12 h LD yielded the highest total production and growth (p<.05), with highest (p<.05) survival percentage. This study demonstrated that A. dengizicus can tolerate wide range of environmental conditions and can be cultured for commercial live feed purposes as well as toxicity studies
Performance Investigation of Dual Wavelength Fiber Laser using different SOAs
We investigated the performance of a dual wavelength fiber laser (DWFL) using different types of semiconductor optical amplifiers (SOAs) utilizing fiber Bragg gratings (FBGs) as comb filter. The lasing performances of linear SOA (LSOA), nonlinear SOA (NLSOA) and booster optical amplifier (BOA) at different current setting were observed. LSOA produced the flattest spectrum based on its peak power difference at only 4.5 dB as compared to 66.4 dB using BOA. BOA has the worst flatness because its polarization sensitivity is the highest as compared to LSOA and NLSOA. Overall, the best lasing performance is when LSOA is used due to the lowest peak power difference with high peak power at -17.6 dBm
Factors affecting the role of human resource department in private healthcare sector in Pakistan: a case study of Rehman Medical Institute (RMI)
The role of Human Resource Management in healthcare sector and challenges it faces has always been an important area of research both in developed and developing countries. The objective of this study is to evaluate the role of HR department in private healthcare sector in the province of Khyber Pakhtunkhwa (KPK), Pakistan and to analyze the challenges/factors affecting the role of HR department. Being the largest private sector hospital in KPK the researchers have selected RMI as a case for this study. Data was collected through interviews from different levels of employees in RMI. Constant comparative method was used for analyzing the data. Results present that HR department plays the role of an administrative expert in RMI. The major internal factors include workload, top management interference, management style and organizational culture which negatively effect motivation, performance and morale of the employees. While small labour market, undue interference of government and other higher authorities and trade unions are the external factors that affect the role of HR department in RMI. All these external factors create difficulties for HR department to attract and retain the desired workforce
Characterization of Wideband Semiconductor Optical Amplifiers based on OptiSystem and MATLAB
A study about different types of semiconductor optical amplifiers (SOA)s - linear, nonlinear and in-line SOAs modelling is carried out. The SOA key performance characteristics covered in this paper include optical gain, power, and amplified spontaneous emission (ASE) noise figure. These characteristics definition are included in this work together with the tabulation of each SOA specification parameter operating in the operational conventional (C-) band. The first modelling of SOA wideband travelling wave (TW) component is done through a simple configuration using OptiSystem software. Next, the second modelling method is simulated through numerical steady-state model using MATLAB software. Each graphical result is explained and discussed according to the operational characteristic theories of SOA along with the evaluation for the best performance among the types of SOAs. The contrasted result among them had shown that linear SOA has the most ideal and competitive characteristics, as compared to the nonlinear and in-line SOAs, especially a better choice as gain medium in the multiwavelength fiber laser (MWFL) application
An overview of moisture damage performance tests on asphalt mixtures
This paper presents a review of moisture damage performance tests on asphalt mixtures. The moisture damage remains to be a detriment to the durability of the Hot Mix Asphalt (HMA) pavement. Moisture damage can be defined in forms of adhesive failure between bitumen and aggregates and cohesive failure within bitumen. Aggregate mineralogy, bitumen characteristics and anti-stripping additive dominantly influence the performance of asphalt mixtures towards moisture damage alongside construction methods, climate and traffic loading. Various laboratory test methods have been developed to quantify the moisture damage performance of asphalt mixtures by resembles the action in the field, including qualitative test such as Boiling Water Test (ASTM D3625) and quantitative tests such as Modified Lottman Test (AASHTO T283). Both of these tests consist of two phases, which are conditioning and evaluation phase. This paper will review the effectiveness of the selected available tests based on various asphalt mixtures materials. Generally, this study indicates that asphalt mixtures consisted of limestone aggregates, modified bitumen and addition of anti-stripping additives will provide more resistant towards moisture damage
Fuzzy logic controlled miniature LEGO robot for undergraduate training system
Fuzzy logic enables designers to control complex systems more effectively than traditional approaches as it provides a simple way to arrive at a definite conclusion upon ambiguous, imprecise or noisy information. In this paper, we describe the development of two miniature LEGO robots, which are the line following and the light searching mobile robots to provide a better understanding of fuzzy logic control theory and real life application for an undergraduate training system. This study is divided into two parts. In the first part, an object sorter robot is built to perform pick and place task to load different colour objects on a fuzzy logic controlled line following robot which then carries the preloaded objects to a goal by following a white line. In the second part, an intelligent fuzzy logic controlled light searching robot with the capability to navigate in a maze is developed. All of the robots are constructed by using the LEGO Mindstorms kit. Interactive C programming language is used to program fuzzy logic robots. Experimental results show that the robots has successfully track the predefined path and navigate towards light source under the influence of the fuzzy logic controller; and therefore can be used as a training system in undergraduate fuzzy logic class
Prediction of slope failures using bivariate statistical based index of entropy model
The main objective of this research is to evaluate the spatial prediction of potential slope failures in Kuala Lumpur and surrounding areas using an index of entropy based statistical model. Based on potential information of entropy method (IoE), subjective weights were calculated for fourteen landslide conditioning factors used in this study such as, (slope, aspect, curvature, altitude, surface roughness, lithology, distance from faults, NDVI (normalized difference vegetation index), land cover, distance from drainage, distance from road, SPI (stream power index), soil type and precipitation). A landslide inventory map of the study area was produced using previous reports and aerial photographs interpretation aided with extensive field survey and total of 220 main scarps were identified. Out of this, 153 (70%) landslide locations were used to build the IoE model, while remaining 66 (30%) landslide locations were used for validation purpose. For validation, the area under the curve (AUC) was used to quantify the predictive performance of the employed IoE model. The validation results show that the prediction accuracy of the model is 0.80 (80%) and the success rate equals to 0.81 (81%) that consider fine indicator of the reliability of bivariate model based IoE model employed in this study
Advances in solution-processed near-infrared light-emitting diodes
Near-infrared light-emitting diodes based on solution-processed semiconductors, such as organics, halide perovskites and colloidal quantum dots, have emerged as a viable technological platform for biomedical applications, night vision, surveillance and optical communications. The recently gained increased understanding of the relationship between materials structure and photophysical properties has enabled the design of efficient emitters leading to devices with external quantum efficiencies exceeding 20%. Despite considerable strides made, challenges remain in achieving high radiance, reducing efficiency roll-off and extending operating lifetime. This Review summarizes recent advances on emissive materials synthetic methods and device key attributes that collectively contribute to improved performance of the fabricated light-emitting devices
Chromosomal 16p microdeletion in Rubinstein-Taybi syndrome detected by oligonucleotide-based array comparative genomic hybridization: a case report
<p>Abstract</p> <p>Introduction</p> <p>Chromosomal aberrations of chromosome 16 are uncommon and submicroscopic deletions have rarely been reported. At present, a cytogenetic or molecular abnormality can only be detected in 55% of Rubinstein-Taybi syndrome patients, leaving the diagnosis in 45% of patients to rest on clinical features only. Interestingly, this microdeletion of 16 p13.3 was found in a young child with an unexplained syndromic condition due to an indistinct etiological diagnosis. To the best of our knowledge, no evidence of a microdeletion of 16 p13.3 with contiguous gene deletion, comprising cyclic adenosine monophosphate-response element-binding protein and tumor necrosis factor receptor-associated protein 1 genes, has been described in typical Rubinstein-Taybi syndrome.</p> <p>Case presentation</p> <p>We present the case of a three-year-old Malaysian Chinese girl with a <it>de novo </it>microdeletion on the short arm of chromosome 16, identified by oligonucleotide array-based comparative genomic hybridization. Our patient showed mild to moderate global developmental delay, facial dysmorphism, bilateral broad thumbs and great toes, a moderate size atrial septal defect, hypotonia and feeding difficulties. A routine chromosome analysis on 20 metaphase cells showed a normal 46, XX karyotype. Further investigation by high resolution array-based comparative genomic hybridization revealed a 120 kb microdeletion on chromosomal band 16 p13.3.</p> <p>Conclusion</p> <p>A mutation or abnormality in the cyclic adenosine monophosphate-response element-binding protein has previously been determined as a cause of Rubinstein-Taybi syndrome. However, microdeletion of 16 p13.3 comprising cyclic adenosine monophosphate-response element-binding protein and tumor necrosis factor receptor-associated protein 1 genes is a rare scenario in the pathogenesis of Rubinstein-Taybi syndrome. Additionally, due to insufficient coverage of the human genome by conventional techniques, clinically significant genomic imbalances may be undetected in unexplained syndromic conditions of young children. This case report demonstrates the ability of array-based comparative genomic hybridization to offer a genome-wide analysis at high resolution and provide information directly linked to the physical and genetic maps of the human genome. This will contribute to more accurate genetic counseling and provide further insight into the syndrome.</p
Linear and nonlinear fractional hereditary constitutive laws of asphalt mixtures
The aim of this paper is to propose a fractional viscoelastic and viscoplastic model of asphalt mixtures using experimental data of several tests such as creep and creep recovery performed at different temperatures and at different stress levels. From a best fitting procedure it is shown that both the creep one and recovery curve follow a power law model. It is shown that the suitable model for asphalt mixtures is a dashpot and a fractional element arranged in series. The proposed model is also available outside of the linear domain but in this case the parameters of the model depend on the stress level
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